The proposed research will investigate the structure and function of surface membranes as they relate to ionic permeabilities, transport and excitation. In the excitable cells, such as nerve and muscle, the surface membrane elements which regulate specific ion permeabilities will be investigated physically and biochemically and attempts made at identifying the specific membrane regulatory components. In these studies, artificial bimolecular lipid membranes between two liquid phases will be used to reconstitute and determine the function of components extracted from excitable tissue. The ionic permeabilities and excitable properties of the reconstituted membranes will be examined and compared with similar functions in the native cells. The objectives of this research are to identify and isolate those components in the cell surface membrane which are responsible for ion transport and excitability.